Is there a solid AH guide for complete noobs like myself?

When it comes to the AH, I'm pretty much an idiot. I don't understand pricing at all in this game and I can't even begin to understand how people can drop 20+ million gold on one item.

Are there any guides out there for what items/stats are really worth? Are there any rules of thumbs for unidentified items? I know in-game economies change but I really have no idea how this works.

I feel like I could make some cash selling 61+ items but I don't have the slightest clue what slot pieces people are buying and what's a reasonable price to sell them at.

Any tips for a noob trying to make some cash so he can get some upgrades to help make Act 3 easier?